Preheat the oven to 350°F (175°C). Set out two ungreased 13 × 18-inch light-colored aluminum half-sheet pans.

Beat the peanut butter, granulated sugar, and egg in a medium bowl with an electric mixer until smooth and creamy.

Roll the dough into 1-inch balls. Arrange them 2 inches apart on the baking sheets and flatten each one with a fork in a crisscross pattern.

Bake for 9–11 minutes, aiming for about 10 minutes, until the edges are firm. The centers may remain soft while hot.

Cool on the pans for 5 minutes. Transfer the cookies carefully to a wire rack and cool completely for approximately 20 minutes.